The nature of the radicals formed from benzopyrene (BP) under a variety of conditions is being investigated. Conditions include photolysis to form the 6-oxy BP radical, heating to form an unknown radical species, and oxidation with I2, HxSO4 or trifluoroacetic acid to form a cationic species. The radicals formed will be characterized by esr and optical spectroscopies and the mechanism of their formation will be investigated. Since one or more of the radicals fored from BP may be the ultimate carcinogenic form of BP and since antioxidants have been shown to provide protection against the carcinogenic effect of BP, it is also proposed to study the reactions of selected antioxidants with the radicals formed from BP.